12 research outputs found
Dynamics of orientational ordering in fluid membranes
We study the dynamics of orientational phase ordering in fluid membranes.
Through numerical simulation we find an unusually slow coarsening of
topological texture, which is limited by subdiffusive propagation of membrane
curvature. The growth of the orientational correlation length obeys a
power law with in the late stage. We also discuss
defect profiles and correlation patterns in terms of long-range interaction
mediated by curvature elasticity.Comment: 5 pages, 3 figures (1 in color); Eq.(9) correcte
Critical behavior of weakly-disordered anisotropic systems in two dimensions
The critical behavior of two-dimensional (2D) anisotropic systems with weak
quenched disorder described by the so-called generalized Ashkin-Teller model
(GATM) is studied. In the critical region this model is shown to be described
by a multifermion field theory similar to the Gross-Neveu model with a few
independent quartic coupling constants. Renormalization group calculations are
used to obtain the temperature dependence near the critical point of some
thermodynamic quantities and the large distance behavior of the two-spin
correlation function. The equation of state at criticality is also obtained in
this framework. We find that random models described by the GATM belong to the
same universality class as that of the two-dimensional Ising model. The
critical exponent of the correlation length for the 3- and 4-state
random-bond Potts models is also calculated in a 3-loop approximation. We show
that this exponent is given by an apparently convergent series in
(with the central charge of the Potts model) and
that the numerical values of are very close to that of the 2D Ising
model. This work therefore supports the conjecture (valid only approximately
for the 3- and 4-state Potts models) of a superuniversality for the 2D
disordered models with discrete symmetries.Comment: REVTeX, 24 pages, to appear in Phys.Rev.